Creating and Harvesting a Standing Wave

[Bob Smith]

One way to produce a standing wave is via a feedback system - say where a coil picks up the inductive kickback from a pulsed primary coil. The inductive kickback or bemf, as many here call it, can be sent back to the primary using a diode. Now you have two pulses coming into the primary, and soon you have a standing wave due to their interaction. The trick is to harvest the standing wave without disturbing the primary's resonance, and this is by using a pickup coil with a different configuration, perhaps series-wound bifilar.
Bob

[wayne.ct]

Frequency control of Joule Thief circuits

I have built J-T circuits with resonances from as low as 4,000 Hz to as high as 45,000,000 Hz. Maybe you could use something like that to harvest energy from a resonant circuit. Or, on the other hand, use a J-T to restore the losses in your primary resonant circuit. Don Smith had some interesting experiments having to do with what you are saying. I don't have the time and money to do everything I have thought of but I keep thinking about how it might be done.

[Bob Smith]

Wayne,
Lawrence Tseung claims to have produced a standing wave with some of his Joule Theif setups over on the OU forum. You'd have to dig to find it. I think I have it bookmarked, and might be able to post a link to it here.

I think there's a lot that can be done using a simple setup like a JT and feeding the bemf from a secondary back to the core thru a diode. The magnetic flux in the toroid would form a standing wave, as I understand it. I must confess, I haven't tried this; only applying what someone else has said with a similar system.
Good Luck!
Bob

Edit: JT and Standing Wave - some info in this post, more in posts before and after, I think. Getting late, gtg.
http://www.energeticforum.com/renewa...tml#post137102